I have no idea if this is even something that can be addressed, but I'm going to give it a shot.

The way that Gmail works, dots in a username do not matter to Gmail. In other words, first.middle.last@gmail.com and firstmiddlelast@gmail.com will both access the same account with the same password. However, dots in a Blackbaud username do matter and make for unique users, and so first.middle.last@gmail.com would be a separate user and a different BBID than firstmiddlelast@gmail.com.

Trying to explain this to end users is exceptionally complicated and doesn't always end well. In some cases we can't even suggest to users to sign in with Google, because if the BBID doesn't match exactly with the sign in with Google username, BBID will (correctly) not permit access.

If there is a way to code BBID to tell it to ignore dots in a sign in with Google username, that would be great. I don't know if this is exclusive to Google only or if other services have the same issue; I've only ever seen it with Gmail, but that could just be because Gmail is so widely used.